Swivel fixture joint



1949- N. M. RoBBbY 2,477,901 I SWIVEL FIXTURE JOINT Filed April 7, 1948 INVEN TOR. N4 THAN M Poaaoy J MAW/WW Patented Aug. 2, 1949 Uurnazo STATES PATENT? OFFICE SWIVEL FIXTURE'JOINT Nathan M. Robboy, ClevelandHeights; Ohio Application April 7, 1948, Serial No. 19,498

(01. Mel-+862) 1 Claim. 1

This invention relates to electrical fixture joints and particularly to those of a swivel type. This application is a continuation in part of the co-pending application Serial No. 682,199 filed by me on July 9, 1946 for a Swivel fixture joint, now abandoned.

The primary object of this invention is to provide a swivel type electrical joint whose coopcrating elements can be twisted without limit or restriction.

Another object of the invention is to provide a swivel electrical connector that is quickly and easily separable forits rapid assembly and wiring and for the temporary dis-assembly of the fixture joint;

'A further object is to provide a joint'of the type stated which will be safe, free from fire hazard, and positive in its action at all times.

These and other objects of the invention will become apparent from a reading'of the following specification and claims, together with the accompanying drawing wherein like parts are referred to and indicated by like reference characters' and wherein;

Figure 1 is'a side elevation of the assembled ii jointwith a portion thereof'broken away to show th'e construction'and the relation of its various elements;

Figure 2 isa view, partly in section, showing the elements ofthe swivel joint in their separated condition;

Figure 3 is-a top view of the lower body memher taken in the direction of the arrows 3-3 of the Figure 2 Figure 4 is a perspective view of the contact faceof one of the dielectric plate assemblies;

Figure 5 is a perspective'view of' the contact faceof the second or complementary dielectric plateassembly;

Figure 6 is an exploded View of the dielectric plate assembly shown in the Figure 4;

Figure 7 is an exploded viewof the dielectric plate assembly shown in the Figure 5; and

Figure 8 is a slightly enlarged perspective view of. one of the conductor rings, showingthe manner 01 mounting the electricalterminal thereon;

Referring to the Figure 1, there is shown a swivel electrical joint'made in accordance with thisinvention. The joint is intended to be'part of'a bracket that supports an electrical device in a lateral position with reference'to a fixed base, as forexample'the incandescent bulb of a bridge type reading lamp.

The'swivel' joint or connector comprises first" and second hollow body members and 30; re-

spectively, which are held in cooperative junctionby the collar 49'; as shown in the Figures 1 and 2. The first body member 20' has a brim 2|; an

external flange 23 spaced from the brim, an outer screw thread 22between the flange and the brim.

A small retainer pin 25 is seated in the shoulder 24 as illustratedywhich pin engages the hereinafterdescribed dielectric plate 50. A threaded hole26 in the wall ofthe first body receives the conduit! I through which a first pair of electrical conductors l2 and' l3 pass and connect with the hereinafter, described terminals63 and 64 of the contactmembers 50 and 64.

The second body member 30 has a brim portion- 3|: an external flange portion 32'and an internal shoulder portion 33;.- A retainer pin 34 is seated 1 in theshoulder portion and a threaded hole 35 in the wall of the body'receives the conduit I 4 3 through which a second pair of electrical conductors l5- and- 16' enters the body member 30.

A- firstadielectric plate made of a suitable electrical non-conductor such as hard rubber,-

plastic, Woodor glass is snugly seated on-the shoulder 24-. of the first-body member 20.

gages-the retaining pin 25 and prevents the rotation .of the-plate relative to the body 20.. Theplate hasltwo ring mounting holes 52-and 53 and two disk mounting. holes. and 55, as shown in the Fi e 6.

Reference. character indicates a flat conductingring having diametricallyspaced mounting. and conducting tabs BI and 62, respectively. Theconductor tab 62 is inserted into a conductor terminal tube 63, which tube iscrimped as at 63a Reference character 64 indicates an embossed conducting disk having diametrically spaced 1 mounting and conducting tabs 61 and 68, re-

spectively. Theconductor tab 68 is inserted into I a conductor terminal tube 69 which is also crimped to securely retain the tab 68 therein similar to the assembly of the heretofore described I elements 62 and 63. Two diametrically spaced embossed or raised portions and 66 are pressed or integrally formed on the disk 64 and serve as resilient *brushes'or electrical contact wipers.

The 1 plate has-a peripherallocator notch 5| that en The disk 64 is mounted on the face of the plate 50 with the mounting tab 61 extending thru the hole 54 and the terminal 69 is attached to the tab 68 and extends thru the hole 55. The tab 61 is bent over on the back of the plate 50 as at 67a, thus anchoring the disk in place. The disk 64 is planarly mounted concentric with the ring 60 and its diameter is such that there is sufiicient space between the embossed disk and the fiat ring to prevent arcing or the passage of current between the disk and ring. Both the ring and disk should be made of a hard, durable and resilient metal having good electric conducting properties. Light gauge Phosphor-bronze sheet is employed in the preferred form of ring and disk, since it possesses all of the required physical and electrical properties. The ends of the electrical conductors l2 and I3 are inserted into the terminal tubes 63 and 69 of the ring and disk 60 and 64, respectively and soldered or crimped in place, somewhat as indicated by the character 63b of the Figure 8 thus making permanent electrical connections, as shown in the Figure 1.

A second dielectric plate 70, similar in conctruction to the first dielectric plate 50, is snugly seated on the shoulder portion 33 of the second body member 30. Reference character ll indicates a peripheral notch which engages the retaining pin 34 to prevent the rotation of the plate 10 relative to the second body member 3!]. The plate 18 also has two ring mounting holes 12 and 13 and two disk mounting holes 14 and 15, as shown in the Figure 7.

Reference character 80 indicates an embossed conducting ring having diametrically spaced mounting and conducting tabs 83 and 84, respectively. The conducting tab 84 is inserted into a conductor terminal tube 85 which is also crimped to retain the tab 84 like the assembly of parts 62 and 63. The embossed ring 8!] is mounted on the face of the plate 10 with the mounting tab 83 and the terminal 85 extending thru the ring mounting holes 'IZand 13,'respecti vely. The tab 83 is bent over as at 83a on the back of the plate 10, thus anchoring the ring in place. Two diametrically spaced embossed or raised portions 8| and 82 are pressed or integrally formed on the ring 80 and serve as resilient brushes or electrical contact wipers, as shown in Figures 2, 3, and. 7.

Reference character 86 indicates a flat conducting disk having diametrically spaced mounting and conducting tabs 81 and 88, respectively. The conductor tab 88 is inserted into a conductor terminal tube 89, which is then crimped the same as the others. The disk 86 is mounted on the face of the plate with the mounting tab 8? extending thru the hole 14 and the terminal 89 extending thru the'hole 15. The tab 81 is bent as at 81c over on the back of the plate Ill, thus an= choring the disk in place. The disk 86 is planarly mounted concentric with the ring 80 and its diameter is such that there is suflicient space between the disk and ring to prevent arcing, as shown in Figure 3. ,The endsof'the electrical conductors l5 and I6 are inserted in the terminal tubes} 85hand 89 of the ring and disk 80 and. 86, respectively, and similarly soldered or crimped in place; thus making-permanent electrical connections, as shown in"the Figure 1.

The two body members, with their respective plates wired and seated as explained above, are thenbrought into opposition. The brim 2| of the first body member is slightly spaced from or is in sliding engagement with the flange portion 32 of the second body member 30, as shown in the Figure 1. The internal threads 4| of the collar 40 are then engaged with the outer screw thread 22 or the first body member and the collar is rotated until it is tightly seated against and firmly engaged with the flange 23, under which condition the internal bead 42 of the collar will be spaced from the body member 30 and will slidably engage the flange 32 thereof. At the same time, the pair of diametrically spaced brushes 8! and 82 of the embossed ring will slidably engage, under tension, the surface of the flat ring 6!). The pair of diametrically spaced brushes 65 and 66 of the embossed disk 6Q will similarly slidably engage under tension the flat disk 86. When the connector is assembled as aforesaid, the various brushes are slightly flattened or deformed and form broad sliding contact surfaces against their mating parts. The only frictional or sliding surfaces of this novel fixture joint are the ones at the concentric Phosphor-bronze electric contacts and the beads 42 with the flange 32. The spring tension of the abutting electric contacts is sufficient to insure a smooth sliding efiect between the said collar and body members and also is sufiicient to retain the respective parts in a normal or set position. The surfaces between the outer wall of the body member 30 between the brim portion 3i and the flange portion 32; and the inner wall of the body member 20 adjacent to the brim 2| are spaced so as not to be under tension or tightly engaged.

The body members 20 and 30 can be rotated with reference to one or the other without limit in either direction. Reference character I la indicates an alternate position of the conduit ii in the Figure 1, in which the conduit is shown removed from its original position.

As will be noted by referring to the Figure 1, the two plates are free to rotate with reference to one another but the notch and pin construction shown most clearly in the Figure 3 prevents the plates from rotating relative to their respective body members. Therefore, the electric conductors I2, I 3, l5 and IE will never become twisted or separated from their respective terminals.

Since the collar 40 is normally seated tightly against the flange 23 of the first body member 28, its bead @2 can never become squeezed against the flange portion 32 of the second body member and thereby cause the connector parts to become jammed.

The diametrically spaced resilient brushes assure a broad wiping contact between the rings and disks at two points, and give the same area of electrical contact as would be afforded by a conventional knife blade switch which has its blade seated between the two wiping surfaces of its split stationary terminal.

In the prior art swivel connectors, there are employed rods, balls or flat matching rings which make the contacts. With the old type of construction, there is only point contact between the moving elements. Even the so-called flat rings have only point contact since no attempt is made to give them a truly flat surface. As a result, such connectors have a high resistance and are limited in the amount of current that can be safely passed through them. A swivel connector made in accordance with this invention can safely carry as much current as its associated circuits, there being no danger of arcing or heating at the contact areas.

Another advantage of a swivel connector made i in accordance with this invention is that there are no spring-pressed rods, washers or balls to fall out when the two halves are separated. The connector can be wired in place on its associated device and then the body members can be separated to make a more compact shipping package, or different devices can be interchangeably mounted on either half of the connector without the use of special tools or skill.

It will now be clear that there has been provided a device that accomplishes the objectives heretofore set forth. While the invention has been disclosed in its preferred form, it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claim.

I claim:

A separable swivel connector, comprising in combination, a first hollow body member having a brim, an internal shoulder thereon spaced from the said brim and having an opening for the passage therethrough of a first pair of electric conductors, the said first hollow body member including an external flange spaced from the said brim and an external screw thread between the said brim and the external flange; a first dielectric plate member stationarily seated on the said internal shoulder and having a flat conducting ring mounted on the face thereof and an embossed conducting disk centrally mounted on the face thereof concentric with and planarly spaced from the said fiat ring, the said embossed conducting disk having a pair of diametrically spaced resilient brush portions integral therewith, each flat ring and embossed disk having a conductor terminal thereon extending through the back .of the first dielectric plate member and con- TI nected to the aforesaid first pair of electric conductors; a second hollow body member having a brim portion and an internal shoulder portion and an external flange portion thereon spaced from the said brim portion, the said second hollow body member also having an opening for the passage therethrough of a second pair of electric conductors; a second dielectric plate member 6 stationarily seated on the said internal shoulder portion and having an embossed conducting ring mounted on the face thereof and a flat conducting disk centrally mounted on the face thereof concentric with and planarly spaced from the embossed conducting ring, the said embossed conducting ring having a pair of diametrically spaced resilient brush portions integral therewith, each embossed ring and flat disk having a conductor terminal thereon extending through the back of the second dielectric plate member and connected to the aforesaid second pair of electric conductors; and a collar member tightly seated on the aforesaid external flange and having an internal screw thread engaged with the aforesaid external screw thread, the said collar member also having an internal bead spaced from the second body member and slidably engageable with the aforesaid external flange portion thereof, the first and second body members and the first and second dielectric plate members being spaced apart, each embossed disk and ring being in tensioned engagement with each flat disk and ring respectively whereby constant uniform electric connection and unlimited rotation may be had between the first and second pairs of electric conductors with minimum frictional contact between the body and collar members and whereby the said plate members and the portions and elements thereof remain intact with their respective body members when the collar member is removed.

NATHAN M. ROBBOY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,174,379 Bacon Mar. 7, 1916 1,238,448 Shaw Aug. 28, 1917 1,241,030 Schade Sept. 25, 1917 1,591,791 Sprout July 6, 1926 1,720,619 Baldwin July 9, 1929 2,116,050 Stock May 3, 1938 2,265,998 Bruno Dec. 16, 1941 2,374,971 Benander May 1, 1945 

